To illustrate the numeric operations you can perform in the SELECT list, you start with a listing of the names, quantity in
stock, and unit price of products in the SQL Anywhere sample database.

SELECT Name, Quantity, UnitPrice
FROM Products;

Name

Quantity

UnitPrice

Tee Shirt

28

9

Tee Shirt

54

14

Tee Shirt

75

14

Baseball Cap

112

9

...

...

...

Suppose the practice is to replenish the stock of a product when there are ten items left in stock. The following query lists
the number of each product that must be sold before re-ordering:

SELECT Name, Quantity - 10
AS "Sell before reorder"
FROM Products;

Name

Sell before reorder

Tee Shirt

18

Tee Shirt

44

Tee Shirt

65

Baseball Cap

102

...

...

You can also combine the values in columns. The following query lists the total value of each product in stock:

SELECT Name, Quantity * UnitPrice AS "Inventory value"
FROM Products;

Name

Inventory value

Tee Shirt

252.00

Tee Shirt

756.00

Tee Shirt

1050.00

Baseball Cap

1008.00

...

...

When there is more than one arithmetic operator in an expression, multiplication, division, and modulo are calculated first,
followed by subtraction and addition. When all arithmetic operators in an expression have the same level of precedence, the
order of execution is left to right. Expressions within parentheses take precedence over all other operations.

For example, the following SELECT statement calculates the total value of each product in inventory, and then subtracts five
dollars from that value.

SELECT Name, Quantity * UnitPrice - 5
FROM Products;

To ensure correct results, use parentheses where possible. The following query has the same meaning and gives the same results
as the previous one, but the syntax is more precise:

SELECT Name, ( Quantity * UnitPrice ) - 5
FROM Products;

Arithmetic operations may overflow because the result of the operation cannot be represented in the data type. When an overflow
occurs, an error is returned instead of a value.

You can concatenate strings using a string concatenation operator. You can use either || (defined by SQL/2008) or + (supported
by Adaptive Server Enterprise) as the concatenation operator. For example, the following statement retrieves and concatenates
GivenName and Surname values in the results:

Columns can be given an alias
By default the column name is the expression listed in the SELECT list, but for calculated columns the expression is
cumbersome and not very informative.

Other operators are available
The multiplication operator can be used to combine columns. You can use other operators, including the standard arithmetic
operators, and logical operators and string operators.

For example, the following query lists the full names of all customers:

The || operator concatenates strings. In this query, the alias for the column has spaces, and so must be surrounded by double quotes.
This rule applies not only to column aliases, but to table names and other identifiers in the database.

Functions can be used
In addition to combining columns, you can use a wide range of built-in functions to produce the results you want.

For example, the following query lists the product names in uppercase: